Miter saw with cutting alignment device on a dust chute

ABSTRACT

A miter saw with a cutting alignment device includes a base with a work surface provided thereon. A bevel support is pivotable with respect to the base and a cutting blade is supported by the bevel support. A dust chute is adjustably secured to the bevel support and pivots with respect to the base when the bevel support pivots. The dust chute includes mounts that allow lateral adjustment of the dust chute with respect to the bevel support. A laser alignment device is positioned on the dust chute and configured to emit a beam of light toward the work surface. The dust chute includes a receptacle designed and dimensioned to releasably hold the laser alignment device. Because the laser alignment device is retained on the dust chute, adjustment of the dust chute also results in adjustment of a beam of light emitted from the laser alignment device.

FIELD

This application relates to the field of power tools and moreparticularly to power saws, such as power miter saws.

BACKGROUND

Power miter saws are typically used for sawing material, for example,construction lumber. The miter saws include a base or platform on whicha turntable is positioned. The turntable is used to support a work piecethereon. A support assembly of the miter saw is connected to theturntable and functions to support a cutting assembly that is operableto perform a cutting operation on the work piece. The support assemblyincludes functionality that enables the cutting assembly to move upwardand away from the turntable and downward toward the turntable in orderto produce a cut. The support assembly also typically includesfunctionality to enable the cutting assembly to pivot in relation to theturntable in order to produce angled cuts. An example of such a mitersaw is disclosed in U.S. Pat. No. 6,769,338 issued to Svetlik et al.

The cutting assembly of the miter saw is relatively heavy because itincludes a motor, a cutting blade, a blade guard, and other structuralcomponents such as those components used to maintain a precise path forthe cutting blade. When the support assembly is pivoted to change theangle of the cut of the cutting assembly, the user must temporarilydisengage a lock that prevents pivoting of the support assembly relativeto the table. Once the lock is disengaged, the user pivots the supportassembly and related cutting assembly to a desired cut angle and thenreengages the lock to prevent further pivoting of the support assembly.This action of unlocking and re-locking the pivotable support assemblyrequires the release and engagement of relatively high forces that maybe difficult for the user to manage. Accordingly, it would be desirableto provide a support assembly arrangement that makes pivoting of thesupport assembly and related cutting assembly easier for the user,including easier disengagement and reengagement of a pivot lock.

Many miter saws include a positive stop arrangement that prevents thesupport assembly and related cutting assembly from pivoting past adesired bevel position. These positive stop arrangements typicallyinclude a two-position toggle capable of stopping the support assemblyat an angle commonly used for compound-angle cuts when cutting trim. Thearrangement typically includes separate override arrangements whichallow the support arrangement to pivot past the most common start andend positions in the event that extra angular capacity is needed.Because these positive stop arrangements include multiple components inmultiple positions, it would be advantageous to simplify the positivestop arrangement into a single control, thereby reducing the cost ofmanufacturing and simplifying operation of the positive stop arrangementfor the user of the miter saw.

It is desirable for miter saw designers to construct a miter saw ascompact as possible. To this end, designers of miter saws attempt tomake the width of the miter saw, measured side to side, as small aspossible. This provides for ease of transport and storage, and reducesspace utilized at a work site. However, users of miter saws oftenrequire a relatively wide support surface that will hold work pieces tobe cut with the miter saw. Accordingly, some miter saws have beenprovided in the past with extendable work surfaces. However, many ofthese extendable work surfaces remain undesirably large for packaging,transport and storage. Accordingly, it would be desirable to provide awork support surface for a miter saw that is moveable between aretracted position that is relatively compact and an extended positionthat is relatively wide.

In addition to the foregoing, many miter saw arrangements include alaser alignment device. However, it is often difficult for the designerof the saw to find a location on the saw to mount an alignment systemwhere the laser beam is directed to a desired location without physicalobstruction during operation of the saw. Furthermore, certain mountinglocations on the saw will cause the laser beam to shift out of anintended cutting line when the blade of the saw is not in a cuttingposition. Therefore, it would be desirable to provide a miter saw with alaser alignment guide that is mounted in a position that will not resultin obstruction of the laser beam or movement of the laser beam out ofthe cut line. It would also be advantageous if such laser alignmentarrangement could be easily adjusted to properly align the laser alongthe desired cut line. It would also be advantageous if the laseralignment arrangement could be easily and conveniently mounted andadjusted using an inexpensive mounting and adjustment system.

In view of the foregoing, it would be desirable to provide a miter sawwith an improved bevel lock. It would also be desirable to provide amiter saw with an improved positive stop arrangement. Additionally, itwould also be desirable to provide a miter saw with an improvedextension support arrangement. Furthermore, it would be desirable toprovide a miter saw with an improved laser alignment system. While itwould be desirable to provide a miter saw that provides one or more ofthese or other features, the teachings disclosed herein extend to thoseembodiments which fall within the scope of the appended claims,regardless of whether they accomplish one or more of the above-mentionedadvantages or include one or more of the above-mentioned features.

SUMMARY

A miter saw with a cutting alignment device includes a base with a worksurface provided thereon. A bevel support is pivotable with respect tothe base and a cutting blade is supported by the bevel support. A dustchute is secured to the bevel support and is pivots with respect to thebase when the bevel support pivots. A laser alignment device ispositioned on the dust chute and configured to emit a beam of lighttoward the work surface.

The dust chute includes a receptacle designed and dimensioned toreleasably hold the laser alignment device. In at least one embodiment,the receptacle comprises a cup shaped member configured to receive acartridge of the laser alignment device, the cartridge including opticsand a laser generator. The laser generator may be configured to emit abeam of light along each side of the cutting blade toward the worksurface.

The dust chute further comprises an input port positioned on a forwardside of the bevel support such that the input port is open to thecutting blade. The dust chute further includes an output port positionedon a rearward side of the bevel support. The input port is generallylarger than the output port with funnel walls positioned between theinput port and the output port. In at least one embodiment, the dustchute is adjustably mounted on the bevel support. The dust chuteincludes at least one mounting tab with a slot provided in the mountingtab. A fastener extends through the slot in the at least one mountingtab. The slot is elongated such that the dust chute may be moved in alateral direction when the fastener extends though the slot. Thefastener may comprise a screw that threadedly engages a hole in thebevel support. The screw includes a head configured to engage the dustchute when the screw is tightened in the hole in the bevel support.

The above described features and advantages, as well as others, willbecome more readily apparent to those of ordinary skill in the art byreference to the following detailed description and accompanyingdrawings. While it would be desirable to provide a miter saw arrangementthat provides one or more of these or other advantageous features, theteachings disclosed herein extend to those embodiments which fall withinthe scope of the appended claims, regardless of whether they accomplishone or more of the above-mentioned advantages or include one or more ofthe above-mentioned features.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a front perspective view of a miter saw assembly;

FIG. 2 shows a rear perspective view of the miter saw assembly of FIG.1;

FIG. 3 shows a front perspective view of the miter saw assembly of FIG.1 with a cutting arrangement pivoted away from a turntable;

FIG. 4 shows a rear perspective view of a bevel lock arrangement of themiter saw assembly of FIG. 1;

FIG. 5 shows a close-up view of the bevel lock arrangement of FIG. 4;

FIG. 6 shows a side view of the bevel lock arrangement of FIG. 4;

FIG. 7 shows a close-up view of the bevel lock arrangement from anopposite side of the bevel post from that shown in FIG. 6;

FIG. 8 shows a rear view of the bevel lock arrangement of FIG. 4;

FIG. 9A shows a side perspective view of the bevel lock arrangement ofFIG. 4 showing the clamp arm extending into an opening in the bevelpost;

FIG. 9B shows a front perspective view of the bevel lock arrangement ofFIG. 9A with the bevel post shown in phantom to expose the connectionbetween the lever and the clamp arm;

FIG. 10 shows a cross-sectional view of the bevel lock arrangement ofFIG. 9A showing a cam engaging the clamp arm;

FIG. 11A shows a cross-sectional view of an alternative embodiment of acam member engaging the clamp arm of FIG. 10 from a reverse side;

FIG. 11B shows a the cam member of FIG. 11A rotated resulting inmovement of the clamp arm;

FIG. 12A shows an alternative embodiment of an actuator for the clamparm of FIG. 10 with the actuator in an unlocked position;

FIG. 12B shows the actuator of FIG. 12A moving toward a locked position;

FIG. 12 C shows the actuator of FIG. 12A in a locked position;

FIG. 13 shows a side view of the miter saw of FIG. 1 showing the beampath of a laser alignment device passing alongside the blade of thecutting arrangement;

FIG. 14 shows a reverse side perspective view of the miter saw of FIG.13 with the cutting arm and blade guard removed from the figure to showplacement of the laser alignment device on a dust chute;

FIG. 15 shows a front perspective view of the laser alignment device ofFIG. 14;

FIG. 16 shows a close-up view of the laser alignment device of FIG. 15positioned on a receptacle on the dust chute;

FIG. 17 shows a side view of the laser alignment device positioned inthe receptacle of FIG. 16;

FIG. 18 shows a front perspective view of the miter saw assembly of FIG.1 with support extensions shown on the sides of the turntable;

FIG. 19 shows a bottom view of the miter saw assembly of FIG. 18 showingslideable guide rods extending through the base;

FIG. 20A shows a top view of the miter saw assembly of FIG. 18 with thesupport extensions in a retracted position;

FIG. 20B shows a top view of the miter saw assembly of FIG. 20A with thesupport extensions in an extended position;

FIG. 21 shows a cross-sectional view of a locking arrangement for thesupport extensions of FIG. 20B;

FIG. 22A shows a perspective view of a multi-position bevel stop togglefor use with the miter saw arrangement of FIG. 1;

FIG. 22B shows a perspective view of retaining features for use with thebevel stop toggle of FIG. 22A; and

FIG. 23 shows an alternative embodiment of the multi-position bevel stoptoggle of FIG. 22A.

DESCRIPTION

Referring now to FIGS. 1-3, there is shown a miter saw assembly 100. Themiter saw assembly 100 includes a base 102 and a turntable 104 that isrotatable on the base 102. The miter saw assembly 100 further includes acutting head 106 mounted on a cutting head support assembly 114. Thecutting head 106 (which may also be referred to herein as a “cuttingassembly”) includes a motor 108 that is operable to rotate a circularsaw blade 110. The cutting head support assembly 114 is attached to theturntable 104 and configured to support the cutting head 106 such thatthe cutting head may move over the turntable 104 and perform cuttingoperations.

The cutting head support assembly 114 includes a bevel arm 116, acutting arm 118, a first pivot mechanism 120, and a second pivotmechanism 122. The bevel arm 116 (also referred to herein as a “bevelpost”) provides a bevel support structure for the miter saw assembly.The bevel arm 116 is pivotally attached to the turntable 104 by thefirst pivot mechanism 120. The first pivot mechanism 120 includes ahinge arrangement that enables the bevel post 120 of the supportassembly 114 to pivot with respect to the turntable during a setupprocedure. In particular, this arrangement is configured to enable thecutting assembly 106 to pivot about axis 124 from a vertical position(as shown in FIGS. 1-3) to an angle of 45° (not shown) or more in theleftward direction prior to a cutting operation. This pivoting allowsthe blade 110 of the cutting assembly 106 to approach the table 104 froma bevel angle and perform angled cuts, as is well known in the art.

The cutting arm 118 of the support assembly 114 provides a support forthe cutting assembly 106. The cutting arm 118 is pivotably connected tothe bevel arm 116 via the pivot mechanism 122. The pivot mechanism 122enables pivoting movement of the cutting assembly 106 in relation to theturntable 104 and the base 102 during a cutting operation. Inparticular, the second pivot mechanism 122 includes a hinge that enablesthe cutting arm 118 to pivot with respect to the bevel arm 116 about anaxis 126. This pivoting allows the blade 110 of the cutting assembly 106to move toward and away from a horizontal turntable 104 to perform acutting operation, as is well known in the art.

The cutting assembly 106 includes a handle 128 connected to the cuttingarm 118 to facilitate movement of the cutting assembly 106 in relationto the turntable 104. The handle 128 is designed and dimensioned to begrasped by a human hand when performing a cutting operation. This allowsthe user to easily pivot the cutting assembly 106 about axis 126. Aswitch 112 is provided on the handle 128 to allow the user to easilyenergize and de-energize the electric motor 108 during a cuttingoperation. A blade guard 136 covers the top portion of the circular sawblade 110.

The circular saw blade 110 includes a generally circular plate having acentral opening defined therein. A plurality of cutting teeth areattached to periphery of the plate, as is well know in the art. A dustchute 132 (which may also be referred to herein as a “dust conduit”) issecured to the bevel post 116 such that pivots with the bevel postrelative to the turntable 104. As shown in FIGS. 1 and 2, the dust chute132 is positioned behind the blade 110 when the blade is in a downwardcutting position. In this manner, the dust chute 132 receives sawdustand other debris created by the blade 110 when performing a cuttingoperation.

The circular saw blade 110 is used to cut a work piece (not shown)positioned on or over the base 102. Accordingly, the base includes awork surface configured to support the work piece. The work surfaceincludes the rotatable turntable 104 as well as laterally moveable worksurface extensions 130 (which may also be referred to herein as “supportextensions”). As shown in FIG. 3, and as explained in further detailbelow, the support extensions 130 are moveable to an extended positionin order to better support a work piece on the miter saw. A rip fence134 is secured to the base 102 and positioned over the turntable 104 foraligning a work piece thereon, as is known in the art. In addition tothe above description, various additional features and assemblies areprovided of the miter saw assembly 100 to assist the user in controllingthe miter saw and obtaining a desired cut on the work piece, asexplained in further detail below.

Bevel Lock

With reference now to FIGS. 4-8, a bevel lock arrangement 150 for themiter saw assembly 100 is shown. The bevel lock arrangement 150 includesa rotor 152, a forward brake pad 154, a rearward brake pad 156, a clampmember 158, and a pivotable handle 160. The handle 160 is configured tomove the clamp member 158 between a lock position and an unlockposition. When in the lock position, the clamp member 158 forces theforward brake pad 154 into tight engagement with the rotor, trapping therotor between the forward brake pad 154 and the rearward brake pad 156and locking the bevel arm 116 in place.

The rotor 152 provides a locking plate for the bevel lock arrangement150. The rotor 152 is an arcuate member that is fixed to the turntablewith bolts 162. The rotor 152 is substantially rigid and may becomprised of a metal material or a plastic material. In at least oneembodiment, the rotor 152 is an arcuate plate structure that providestwo opposing substantially flat locking surfaces 153 (i.e., a firstlocking surface on one side of the arcuate plate and a second lockingsurface on the opposite side of the arcuate plate). While the disclosedembodiment shows that the locking surfaces 153 are generally planar andflat, in other embodiments the locking surfaces on the rotor 152 may notbe planar and flat in shape, and may instead be conical in shape or takeon any of numerous other shapes. The locking surfaces 153 are designedto engage the brake pads 154, 156. The rotor 152 and its lockingsurfaces 153 are oriented substantially perpendicular to the work piecesupport surface 105 provided by the table 104. The arcuate shape of therotor 152 allows the brake pads 152, 154 to follow the locking surfaces153 as the bevel post 116 is rotated.

The brake pads 154, 156 provide high friction surfaces that engage therotor 152 and are complimentary in shape to the locking surfaces 153 ofthe rotor. Accordingly, in the disclosed embodiment, the high frictionsurfaces are substantially flat. However, if the locking surfaces 153are differently shaped, the brake pads may be configured with acomplimentary shape to provide greater surface area contact between therotor 152 and the brake pads 154, 156. In at least one embodiment, thehigh friction surfaces of the brake pads 154, 156 are comprised of asemi-metallic ceramic composite material, similar the material used forautomotive brake pads. In another alternative embodiment, the highfriction surfaces of the brake pads 154, 156 may be comprised of anatural or synthetic rubber or other elastomer material. Alternatively,the brake pad surfaces may be comprised of a felt or other fabric.Preferably, the brake pads 154, 156 are comprised of a material thatdoes not easily slide on the surface of the rotor 152. In the disclosedembodiment, the brake pads 154, 156 are singular on each side of therotor 152 generally rectangular or trapezoidal in shape. In otherembodiments the brake pads 154, 156 may be provided in other shapes(e.g., circular, etc.) or may comprise a plurality of pads on each sideof the rotor 152. The high friction surfaces may be secured on the brakepads 154, 156 by any of various processes or may be integrally formed onthe brake pads. In the disclosed embodiment, the high friction surfacesare heat pressed onto a metal substrate which includes locating/mountingfeatures for the brake pads 154, 156.

The forward brake pad 154 is fixed to the bevel post 116 and isconfigured to engage the substantially flat forward surface of the rotor152. The rearward brake pad 156 is retained by the clamp member 158 andis configured to engage the substantially flat rearward surface 153 ofthe rotor 152. The rearward brake pad 156 includes a center post 157 orother mounting structure that is attached to the high friction surfaceand helps retain the brake pad 156 on the clamp member 158. As shown inFIG. 10, the center post 157 extends away from the high friction surfacethat engages the rotor 152 and into a hole in the clamp member 158.

The clamp member 158 is pivotably connected to the bevel arm 116 at ahinge structure 164 using a pivot pin 166 (see FIG. 7). The entire clampmember 158 is best seen in FIGS. 9 and 10 and includes a pivot end 170,clamp portion 172, and an actuator arm 174. The pivot end 170 of theclamp member 158 includes a channel that receives the pivot pin 166 ofthe hinge structure 164, allowing the clamp member 158 to pivot withrespect to the bevel arm 116.

As mentioned above, the clamp portion 172 of the clamp member 158 isconfigured to retain the brake pad 156, with the brake pad 156 moveablerelative to the clamp member 158. As best seen in FIGS. 7 and 10, thebrake pad 156 is retained by the center post 157 that extends through acenter hole in the clamp member 158. When the brake pad 156 movesrelative to the clamp member 158 this post 157 moves within the hole ofthe clamp member 158.

A recess 176 is formed between the brake pad 156 and the clamp portion172. A spring stack 178 and a leveling plate 180 are positioned in therecess 176 and rest upon the center post 157 extending from the brakepad 156. Because of its position between the brake pad 156 and the clampmember 158, the spring stack 178 biases the brake pad 156 away from theclamp member 158 and toward the rotor 152. Even though the brake pad 156is retained by the clamp member 158, the brake pad 156 is moveablerelative to the clamp member 158, and the spring stack 178 is compressedand decompressed as the brake pad 156 moves toward and away from theclamp member 158. An adjustment screw 182 may be used to connect thespring stack 178 to the clamp portion 172 of the clamp member 158. Theadjustment screw 182 may be tightened or loosened to adjust the positionof the spring stack 178 relative to the clamp member 158. If the springstack 178 is moved further away from the clamp portion 172 by theadjustment screw, more force is required to lock the clamp member 158since more spring 178 compression is required when the clamp member 158forces the brake pad 156 against the rotor 152. However, if the springstack 178 is allowed to move closer into the clamp portion 172 by theadjustment screw, less force is required to lock the clamp member 158since less spring 178 compression is required when the clamp member 158forces the brake pad 156 against the rotor 152.

With particular reference now to FIGS. 9-11B, the actuator end 174 ofthe clamp member 158 is provided as an arm that extends away from theclamp portion 172. The actuator end 174 of the clamp member 158 includesa channel 175 that receives a shaft 184. The shaft 184 is secured to thebevel post 116 and is rotatable about axis 188. One end of the shaft 184rotatably engages the channel 175 of the clamp member 158 and anopposite end of the shaft 184 is fixed to the handle 160.

As shown in FIG. 10, an eccentric arrangement in the form of a cam 186is provided on a portion of the shaft 184 that is positioned within thechannel 175. The shaft 184 is allowed to rotate about the axis 188, butis otherwise held stationary relative to the bevel post 116. When theshaft 184 rotates, the cam 186 engages the interior wall of the channel175, causing the position of the clamp member 158 to shift between aclamping position and a loosened position.

FIGS. 11A and 11B show a close-up view of the cam 186 and clamping arm158 arrangement shown in FIG. 10. As mentioned above, the cam 186 ispositioned on the shaft 184 that is connected to the handle 160. Theclamping arm 158 is configured to pivot between the position shown inFIG. 11A and the position shown in FIG. 11B (compare position of clampmember 158 to line 189 extending through each axis 188 in FIGS. 11A and11B). The handle 160 acts as an actuator in the form of a lever.Movement of the lever 160 results in rotation of the shaft 184, therebycausing the clamp member 158 to pivot between a clamping position and afree position.

In operation, a user may set up the miter saw arrangement 100 startingwith the handle 160 in an unlocked position. With the handle in theunlocked position, the bevel post 116 is free to pivot relative to thetable 104. After moving the cutting arrangement to a desired bevelposition, the user then locks the bevel post 116 in the desired positionby rotating the handle 160 to a locked position. When the handle 160 isrotated, the cam 186 engages the clamp member 158, causing the clampmember 158 to pivot about pin 166 on the bevel post and toward the rotor152. When the clamp member 158 pivots toward the rotor 152, the rearwardbrake pad 156 is forced against the rotor 152 by the clamp member 158and connected spring stack 178. The force of the brake pad 156 againstthe surface 153 of the rotor 152 also causes the rotor 152 to be forcedagainst the forward brake pad 154 which is secured to the bevel post116. Thus, the brake pads 154 and 156 clamp down on the rotor 152 andlock the bevel post 116 in place at the desired bevel angle.

While the foregoing is but one embodiment of the bevel lock arrangement,it will be appreciated that other embodiments are also possible. Forexample, FIGS. 12A-12C show an alternative embodiment where the actuatorand clamp member 158 are provided as part of a four bar linkagearrangement. FIG. 12A shows a schematic representation of such a fourbar linkage arrangement with the various bars of the linkage labeled.The first bar (not labeled) is provided by the bevel post and is astationary linkage. The second bar is the clamping member 158 with thebrake pad 156 attached to the clamping member 158. The second bar 158 ispivotable about pivot pin 166 of the hinge arrangement 164. The thirdbar 190 is pivotably connected to the second bar 158. The fourth bar 192is pivotably connected to the third bar 190 and the bevel post 116. Thehandle (not shown) may be connected to the third bar 190 or the fourthbar 192. A lock stop 194 is connected to the bevel post 116 and limitsmovement of the four bar linkage once the linkage is in a lockedposition.

In order to move the linkage from the unlocked position of FIG. 12A tothe locked position of FIG. 12C, a user grasps the handle which servesas a lever for the four bar linkage. The user then moves the handle suchthat the third 190 and fourth 192 bars of the linkage move in thedirection indicated by arrow 196 until the linkage contacts the lockstop 194. With the linkage in this position shown in FIG. 12C, the brakepad 156 is in contact with the rotor 152, and the bevel post 116 islocked in place on the miter saw.

In at least one alternative embodiment, the clamp member 158 itself mayprovide the clamping surface that engages the rotor 152. In thisembodiment, the clamping surface may be a high friction surface providedon the clamp member 158. Alternatively, the rotor 152 could provide thehigh friction surface and the clamp member may simply provide a metallicsurface that is forced against the rotor. Accordingly, it will beapparent that although various embodiments of the bevel post lock aredisclosed herein, numerous other embodiments are possible, and the scopeof any appended claims should not be limited to the disclosedembodiments.

Laser Alignment Device on Dust Chute

With reference now to FIGS. 13-17, the miter saw assembly 100 includes alaser alignment device 200 positioned on the dust chute 132. The laseralignment device 220 comprises a cartridge 202 that houses optics and alaser generator. The laser generator may be any of various lasergenerators known in the art. The laser generator is configured to emitat least one narrow beam of light 204, 206 (shown in dotted lines inFIGS. 13-17) toward the table 104 to indicate a cut to be made with themiter saw assembly 100. The laser generator may be, for example, laserLEDs that emit a narrow beam of light which is directed at an angle ofapproximately 30-80 degrees relative to the table. Although laser LEDsare one embodiment of the light source providing the alignment feature,it should be understood that other light sources and arrangements can beused. For example, regular LED's or incandescent light sources may beused in conjunction with lenses or a slotted mask. Furthermore, whilethe disclosed embodiment includes beams of light 204, 206 shining alongopposite sides of the blade 110 which enable an observer to determine acut position between the laser beams 204, 206, it should be understoodthat such a cut position can also be determined with a light beamshining on only one side of the blade 110.

The dust chute 132 is adjustably positioned on the bevel arm 116 of thesupport assembly 114. As discussed previously, the support assembly 114also holds the cutting head 106 such that the cutting head 106 ispivotable with respect to the bevel arm 116. Although the embodiments ofFIGS. 13-17 show the dust chute 132 positioned on the bevel arm 116 ofthe cutting support assembly 114, it will be recognized that in otherembodiments the dust chute 132 may be positioned on other portions ofthe support assembly 114, such as the cutting arm 118.

With continued reference to FIGS. 13-17, the dust chute 132 includes aninput port 210, an exit port 214, and a funnel body 212 positionedbetween the input port 210 and the exit port 214. The input port ispositioned directly behind the circular blade 110 and is open to theblade 110 such that saw dust and other debris sprayed from the blade 110during cutting will be propelled through the input port 210 and into thedust chute 132. The dust chute 132 is generally comprised of a moldedplastic material and is molded from two halves (i.e., split verticallydown the center) and vibration welded together. It will be recognizedthat the dust chute 132 may also be formed from other materials, such asmetal.

The funnel body 212 of the dust chute 132 includes walls that extendthrough an opening 208 formed between the bevel arm 116 and the cuttingarm 118. In particular, the funnel body 212 passes over the pivotmechanism 122 on the bevel arm 116. The cutting arm 118 is attached tothe pivot mechanism 122, but is positioned to the outside of the funnelbody 212 of the dust chute 132, thus allowing the cutting arm 118 topivot without interference from the dust chute 132.

The funnel body 212 of the dust chute 132 has a larger diameter near theinput port 210 than the exit port 214. Although the lateral diameter ofthe dust chute 132 is substantially uniform from front to back, thevertical diameter gradually tapers down when moving from the input port210 to the exit port 214. Accordingly, the cross-sectional shape of thedust chute 132 near the input port 210 is elongated and substantiallyrectangular while the cross-sectional shape of the dust chute 132 nearthe exit port 214 is substantially circular. This larger opening at theinput port 210 allows the dust chute 132 to effectively collect dust anddebris over a relatively large spray area from the cutting blade andchannel the dust to a smaller area at the exit port 214. The exit port212 is configured to releasably connect to a dust collection bag (notshown). Alternatively, the miter saw assembly may include a vacuumsystem (not shown) having an input line that is connected in fluidcommunication with the exit port 212 of the dust chute 132.

As best seen in FIGS. 15 and 16, the dust chute 132 includes a pluralityof mounting tabs 216 attached to the lower portion of the funnel body212. An elongated lateral slot 218 is provided in each mounting tab 216.A fastener in the form of a threaded screw or bolt 220 extends throughthe elongated slot 218 of each mounting tab 216 and into a threaded holein the bevel arm 116. A shaft of the fastener 220 passes through theelongated slot 218, but the diameter of slot 218 is slightly larger thanthe diameter of the shaft, at least in the elongated direction of theslot. The fastener also includes a head 222 that is forced against thetabs 216 of the dust chute 132 when the fastener is tightened in theassociated hole of the bevel arm 116. This secures the dust chute 132 inplace on the bevel arm 116.

A receptacle 224 is positioned on an upper portion of the funnel body212 of the dust chute 132. The receptacle 224 is configured to receivethe laser alignment device 200 and retain the laser alignment device 200in place on the dust chute 132. In the embodiment of FIGS. 13-17, thereceptacle 224 is provided as a cup shaped member configured toreleasably hold the cylindrical cartridge of the laser alignment device200. The cup shaped receptacle 224 includes an upper opening 226 and alower opening 228. The upper opening 226 is designed and dimensioned topass the cartridge of the laser alignment device 200 such that laseralignment device may be inserted into the receptacle 224. The laseralignment device 200 is held in place in the receptacle 224 by afriction fit. In addition, a lower lip 230 may be provided around thelower opening 228 that prevents the laser alignment device 200 frompassing through the lower opening 228 when it is inserted into thereceptacle 224. The lip 230 provides a lower seat that engages thecartridge of the laser alignment device and prevents the cartridge frompassing through the lower opening 228. However, the lower opening 228 issufficient in size to allow the laser beams generated by the laseralignment device 200 to be emitted out of the receptacle 224 toward thetable 104.

The laser alignment device 200 is inserted into the receptacle from theupper opening 226 with its optics facing the lower opening 228. Thelaser alignment device may include a tab 232 on the rear portion of thedevice that facilitates insertion into and removal from the receptacle224. The tab 232 also facilitates rotation of the laser alignment device200 within the receptacle to allow adjustment of the laser alignmentdevice 200 within the receptacle. The receptacle 224 is oriented on thedust chute 132 such that the laser beams generated by the alignmentdevice 220 will be emitted toward the table 104. As best seen in FIG.16, the laser generator 202 may cause a first laser beam 204 and asecond laser beam 206 to be emitted from the cartridge 202. The firstlaser beam 204 is directed along one side of the cutting blade 110toward the table 104, and the second laser beam 206 is directed alongthe opposite side of the cutting blade 110 toward the table.

The positioning of the laser alignment device on the dust chute providesan unobstructed path for the laser beams 204, 206 to the cutting surface104. This path remains unobstructed by the cutting head 106 and otherparts when the cutting head 106 is moved toward and away from the table104 during the cutting process. Because the laser beams 204, 206 passalongside the blade 110, a user is provided with an indication of wherethe blade 110 will pass during a cutting stroke by viewing the areabetween the laser beams 204, 206. Furthermore, the unobstructed path ofthe laser beams 204, 206 to the cutting surface remains even when thecutting head is moved to a bevel angle by pivoting the bevel arm 116.This is possible because the dust chute 132 and attached laser alignmentdevice 200 are mounted directly on the bevel arm 116 and pivot with thebevel arm 116. Although two light beams 204, 206 are shown in theembodiment of FIG. 16, it will be recognized that in other embodimentsthe laser generator may emit only a single beam of light toward thetable 104.

The dust chute 132 may be easily adjusted in the event the laseralignment device becomes slightly misaligned. For example, if a userfinds that one of the laser beams 204, 206 is shining on the blade 110instead of the cutting surface, the user will want to adjusted the laseralignment device 200 such that it shows the proper cutting path. In thiscase, the user may first try to rotate the laser alignment device 200within the receptacle 224 in an attempt to obtain proper orientation ofthe laser beams. If this does correct the misalignment, the user mayattempt to obtain proper orientation of the laser beams by adjusting theposition of the dust chute 132 and connected laser alignment device 200relative to the bevel arm 116. In particular, the elongated form of theslots 218 on the mounting tabs 216 of the dust chute 132 allows the dustchute 132 to be moved in a lateral direction. To accomplish thisadjustment, the fasteners 220 are slightly loosened such that the headof each fastener 220 is moved away from the associated tab 216. The dustchute 132 may be then be shifted in a lateral direction on the bevelpost 116, causing the laser alignment device 200 to be re-positionedrelative to the cutting blade 110. Once the dust chute is moved to aposition where the laser alignment device 200 is properly oriented, thescrews 220 may be re-tightened in order clamp the heads 222 of thescrews 220 against the mounting tabs 216 and fix the dust chute 132 inplace on the bevel arm 116.

Extendable Work Surface

With reference now to FIGS. 18-21, the miter saw assembly includes abase 102 with an extendable work surface 240 provided on the base. Thework surface 240 is provided by the upper surface 105 of the turn table104 and the upper surface 131 of the support extensions 130 which arepositioned to the side of the table 104. The upper surface 131 of thesupport extensions 130 are substantially planar with respect to theupper surface 105 of the turn table 104. The work surface 240 isdesigned to hold a work piece (not shown) to be cut by the miter saw.

The base 102 is designed to sit in a stationary position on a solidsurface, such as the surface of a work bench. The base is generallycomprised of a hard metal material, such as aluminum, and provides astationary frame that supports the remaining components of the miter saw100. In the disclosed embodiment, the base includes a plurality ofrubber feet 242 (see FIG. 19) which help to level the base 102 andstabilize the base on the solid surface upon which the base rests.

Four guide members in the form of rods 250, 252, 254, 256 extend underthe base 102 and slideably connect the extensions 130 to the base 102.The guide rods are slideably retained in bearing members 260 positionedat various locations on the bottom side of the base 102. The guide rods250, 252, 254, 256 may be provided in various forms, such as, forexample solid metallic rods or beams, plastic tubing, extrusion profiles(which may or may not be circular), or other elongated members. In thedisclosed embodiment, the bearing members 260 are provided as smallsupport ribs with holes with the guide rods running through the holes.FIG. 21 specifically shows a cross-sectional view of the base 102 with aguide rod 250 extending through a hole in the support rib bearing member260. As shown in FIG. 19, stop members in the form of clips 262 areprovided at the end of each rod 250, 252, 254, 256 to prevent the rodfrom sliding completely through the bearing members 260. The lockingclips 262 may be E-ring type snap rings but may alternatively be cotterpins, dowel pins, o-rings, screw heads, or any other arrangement capableof providing an outer stop so the guide rods 250, 252, 254, 256 do notpass through the bearing members 260 and separate from the base 102.

The support extensions 130 of the miter saw assembly 100 are fixed tothe guide rods 250, 252, 254, 256. A left extension is connected toguide rods 250 and 252, and a right extension is connected to guide rods254 and 256. As shown in FIG. 21, guide rod 250 engages a channel 133 inthe extension 130. The guide rod 250 may be secured in the channel 133of the support extension 130 by any of various means, such as, forexample, a friction fit, adhesives, or a fastener such as a screw orbolt.

The upper surface 131 of the extensions 103 have a polygonal,substantially trapezoidal shape. However, an interior edge 246 of eachsurface 131 is arcuate in shape to match the circular perimeter of theturn table 104. These arcuate edges 246 are positioned adjacent to thecircular table top 105 of the turn table 104 when the base is in acompact position, such as that shown in FIGS. 18 and 20A. The supportextensions 130 may be provided in any of various forms such as castaluminum, molded plastic, or any other form sufficient to provide asubstantially flat horizontal surface for work-piece support.

The turn table 104 is generally circular in shape and is rotatablymounted upon the base 102. The turn table 104 is configured to rotateabout a central axis. A locking device 244 is provided on the base 102to allow a user to lock the turn table in a selected position relativeto the base. As discussed previously, the bevel arm 116 is pivotablymounted upon the turn table 104, allowing a user to orient the cuttinghead 106 at an angle relative to the table surface 105.

With reference now to FIGS. 20A and 20B, the extensions 130 areconfigured to move between a compact position (shown in FIG. 20A) and anextended position (shown in FIG. 20B). When in the compact position ofFIG. 20A, the upper surfaces 131 of the extensions 130 are in closeproximity to the surface 105 of the turn table and separated by a smallair gap (e.g., less than one inch apart), with the arcuate inner edges246 of the extensions 130 facing the circular edges of the turn table104.

The extensions 130 and their associated surfaces 131 may be extended outfrom the extreme inward position shown in FIG. 20A by sliding theextensions 130 away from the turn table 104. The extensions 130 andassociated surfaces 131 may be extended as far as an extreme outwardposition as shown in FIG. 20B. As the extensions 130 are extendedoutward, the guide rods 250, 252, 254, 256 slide on the bearing 260surfaces. The bearings 260 allow the guide rods 250, 252, 254, 256 toslide outward until the locking clips 262 of the guide rods contact thebearings 260, thus preventing further outward movement of the guide rods250, 252, 254, 256. When in the extended position of FIG. 20B, the uppersurfaces 131 of the extensions 130 are substantially removed from theupper surface 105 of the turn table 104 (e.g., six or more inchesapart), with no work support surfaces positioned in-between. Instead,when in the extended position of FIG. 20B, only portions of the saw 100below the work support surfaces 105 and 131 are positioned between thework support surfaces 105 and 131. In particular, moving the extensions130 outward exposes portions of the base 102 and the guide rods 250,252, 254, 256 (which are fixed to the extensions 130 and slideablyengage the bearing members 260 on the underside of the base 102).

When the extensions 130 are moved to their desired position, lockingdevices 264 may be used to secure the guide rods and associatedextensions in place. As shown in FIG. 21, each locking device 264comprises a screw 266 that extends through a hole in the base to contacta guide rod 250. The screw 266 includes threads 268 that engagecomplimentary threads in the base. A lever 272 is connected to the head270 of the screw 266. Rotation of the lever 272 results in rotation ofthe associated screw 266. When the lever 272 is rotated to drive thescrew 266 downward, the bottom portion of the screw 266 serves as alocking post that comes into contact with the guide rod 250 and preventsthe guide rod from sliding. This effectively locks the extensions 130and their associated support surfaces 131 in place relative to the turntable 104. While FIG. 21 shows one example of a locking arrangement,various other acceptable arrangements will also be recognized. Forexample, in one alternative locking arrangement, each guide rod wouldrun through a spring loaded piece of steel. The steel would beconfigured to pivot and compress a spring to allow the rod to extend.Release of the steel piece would cause the spring to force the edge ofthe steel into the rod and lock it.

As best seen in FIG. 18, the locking devices 264 are situated under theextensions 130 when the extensions are in the retracted position. Inorder to allow access to the locking devices 264, an opening 276 isformed between a forward edge 277 of each work surface extension 130 anda portion of the base 102 that is directly below the forward edge 277 ofthe extension 130. In at least one embodiment, the opening 276 defines adistance 278 of at least 25 mm between the forward edge 277 of the worksurface extension and the base 102. This distance 278 between theforward edge 277 of the work surface extension 130 and the base 102provides a sufficiently sized opening to allow a user some degree ofaccess to the space under the work surface extension 130 when the worksurface extension is in the retracted position. This clearance distance278 also allows the locking devices to move out from under the worksurface extensions when the extensions 130 are moved to the extendedposition and back under the work surface extensions when the extensions130 are moved to the retracted position.

As described above, the arrangement shown in FIGS. 18-21 provides for amiter saw with an extendable work surface that also has a reducedfootprint. The arrangement provides for a compact miter saw assemblywhere the guide rods 250, 252, 254, and 256 slide out from and retractback into the underside of the base 102. Furthermore, the embodiment ofFIGS. 18-21 makes efficient use of limited surface area by eliminatingany completely fixed support surface portions and instead using therotatable turn table 104 and movable work piece extensions 130. Thisfurther reduces the overall footprint of the miter saw 100 which isadvantageous for shipping, storage, or transportation of the saw.

Multi-Position Bevel Toggle

With reference now to FIGS. 22A and 22B, the miter saw assembly includesa bevel stop member in the form of a multi-position toggle arrangement280. The multi-position toggle arrangement 280 comprises a toggle piece282 that is pivotably mounted to the table 104. The toggle piece 282 isconfigured to engage a protrusion 140 provided on the bevel post 116 inthe form of an adjustable stop bolt. The stop bolt 140 includes a shaftwith an enlarged head that contacts the toggle piece 282 in order tostop the bevel post 116 in a desired bevel position. The shaft of thestop bolt 140 threadedly engages a hole in the bevel post 116. Rotationof the stop bolt 140 places the head of the bolt 140 closer or furtherfrom the bevel post. A locking nut 142 is provided in association withthe bolt 140 to lock the bolt 140 in the desired position relative tothe bevel post 116.

In the embodiment of FIG. 22A, the toggle piece 282 is a pie-shapedmember including a plurality of surface stops 284, a bridge portion 288,and a pivot hole that receives a shoulder screw 286. The shoulder screw286 extends through the pivot hole and into a hole in the table 104. Thetoggle piece 282 is allowed to rotate about this shoulder screw 286 asnoted by arrow 289. In at least one alternative embodiment, the pivothole of the toggle piece is configured to slide over a boss on the tabletop and the shoulder screw 286 which has a larger diameter head than theboss holds the toggle piece 282 in place.

As shown in FIG. 22A, the bridge portion 288 is provided between theshoulder screw 282 and the stops 284. A spring (not shown in FIG. 22A or22B) may be provided between the head of the shoulder screw 286 and awasher 287 that rests on the toggle piece 282. The spring biases thetoggle piece 282 toward the table 10 and prevents the toggle piece 282from rattling during use of the saw 100. This arrangement also providesthe user with some resistance when rotating the toggle piece 282.

With continued reference to FIG. 22A, the plurality of stops 284 areprovided as various blocks having upper surfaces that extend todifferent heights above table 104. The plurality of stops 284 include afirst stop 284 a and a second stop 284 b. Each stop 284 includes anupper surface that is configured to engage the stop bolt 140 to stopmovement of the bevel post 116 at a desired bevel angle. The uppersurfaces on the stops 284 may be inclined relative to the table 104 sothat the force from the stop bolt 140 produces only minimal horizontalreactions on the toggle piece 282.

In the embodiment of FIG. 22A, the first stop 284 a is configured toengage the stop bolt 140 when the bevel post 116 is rotated to a 33.9degree bevel. The second stop 284 b is configured to engage the stopbolt 140 when the bevel post 116 is rotated to a 45 degree bevel.Indicia are provided on the stops 284 to indicate the angle at which thebevel post 116 will stop. In particular, the first stop 284 a includes a“33.9°” inscription and the second stop 284 b includes a 45°inscription. Alternatively, the bevel stop angle for each stop 284 maybe indicated on the table 104.

While two surface stops are shown in FIG. 22A, it will be recognizedthat the multi-position toggle arrangement 280 may further include athird stop block (not shown) having an upper surface which stops thebevel post 116 at a different bevel angle than the first and secondstops 284 (i.e., an angle greater than 45 degrees). In the embodiment ofFIG. 22A, a void 292 is provided at a third stop position. In this case,the third stop position is reached when the toggle 282 is swung to aposition where it will not contact the stop bolt 140 on the bevel post116. With the toggle 282 in this position, the bevel post 116 is free topivot until a dead stop feature (not shown) cast into the bevel post 116hits a cast stop feature on the surface of the table 104 (e.g., at a 48degree or other angle in excess of 45 degrees). Accordingly, the toggleprovides a plurality of stop positions, including a 33.9 degree firststop, a 45 degree second stop, and a third stop in excess of 45 degrees.

With reference now to FIG. 22B, the multi-position toggle arrangement280 is shown with the toggle piece 282 removed to expose retainingfeatures in the form of a detent arrangement 292. Any of three togglepositions on the toggle piece 282 may be selected using the detent 292.In the embodiment of FIG. 22B, the detent 292 is provided by a ball 294and spring 296 held within a detent wall 298. The ball 294 is biasedoutward from an opening in the detent wall 298 by the spring 296. Theopening is smaller than the diameter of the ball 294 so that the balldoes not completely escape the wall 298. The detent wall 298 may be castas part of the table, as shown in FIG. 22B. Alternatively, the detentwall 298 may be separate from the table 104 and fixed to the table withfasteners.

The ball 294 of the detent arrangement 292 is dimensioned to engagecomplimentary divots (not shown) on the interior of the toggle piece282. Each divot is associated with one of the stops 284. Thus, as thetoggle piece 282 is rotated to a desired position, the ball 294 will beforced into the divot associated with the selected stop 284, thusholding the toggle piece 282 in place on the table 104. If a new stop284 is desired, the user rotates the toggle piece 282, forcing the ball294 out of the divot as the toggle piece 282 is rotated. The ball 294will then fall into a new divot when the toggle piece 282 is properlyrotated to a new desired position.

The detent 292 of FIG. 22B provides an arrangement that does not causethe toggle device 282 to lift up off the table 104. Instead, the detentarrangement 292 pushes in a horizontal plane relative to the table,preventing dust and other debris from getting caught beneath the toggle282 and in the detent. However, other detent configurations are possiblefor use with the multi-position toggle arrangement 280, includingvertical detent orientations. In one alternative embodiment, the balland spring shown in FIG. 22B are replaced by a ball plunger set screwthat is screwed into a threaded block on the table. Similar to thearrangement of FIG. 22B, the ball plunger falls into each of the detentdivots in the toggle piece in order to stop the toggle at its desiredlocation.

FIG. 23 shows another alternative arrangement for the multi-positiontoggle arrangement 280. In this embodiment, the toggle piece 282includes a fan-shaped block 300 positioned on the bridge portion 288near the shoulder screw 286. Three indentations in the form of divots302 are formed in the fan-shaped block. Each divot 302 is associatedwith a stop position for the toggle piece 282 and the related stops 284.The detent arrangement includes a detent block 304 with a V-shapedcantilever spring 306. The V-shaped cantilever spring 306 is configuredto pivot such that it engages and disengages the various divots 302 onthe toggle piece 282. A protrusion 308 on the surface of the table 104prevents the toggle piece 282 from rotating past one of the selectablepositions. Similar to the arrangement of FIGS. 22A and 22B, as thetoggle piece 282 is rotated to a desired position in the embodiment ofFIG. 23, the cantilever spring 306 move into the divot 302 associatedwith the selected stop 284, thus holding the toggle piece 282 in placeon the table 104. If a new stop 284 is desired, the user rotates thetoggle piece 282, moving the cantilever spring 306 out of the divot asthe toggle piece 282 is rotated. The cantilever spring 306 will thenmove into a new divot 302 when the toggle piece 282 is properly rotatedto the desired position.

Although the present invention has been described with respect tocertain preferred embodiments, it will be appreciated by those of skillin the art that other implementations and adaptations are possible.Moreover, there are advantages to individual advancements describedherein that may be obtained without incorporating other aspectsdescribed above. Therefore, the spirit and scope of the appended claimsshould not be limited to the description of the preferred embodimentscontained herein.

1. A miter saw comprising: a base with a work surface provided thereon;a cutting support assembly pivotable with respect to the base, thecutting support assembly including a bevel support and a cutting armpivotable with respect to the bevel support; a cutting blade supportedby the cutting arm; a dust chute secured to the cutting supportassembly, wherein the dust chute pivots with respect to the base whenthe cutting support assembly pivots; and a laser alignment devicepositioned on the dust chute and configured to emit a beam of lighttoward the work surface.
 2. The miter saw of claim 1 wherein the dustchute is positioned on the bevel support of the cutting support assemblyand includes an input port positioned on a forward side of the bevelsupport such that the input port is open to the cutting blade, the dustchute further including an output port positioned on a rearward side ofthe bevel support.
 3. The miter saw of claim 2 wherein the input port islarger than the output port with funnel walls positioned between theinput port and the output port.
 4. The miter saw of claim 1 wherein thedust chute is adjustably mounted on the bevel support.
 5. The miter sawof claim 4 wherein the dust chute includes at least one mounting tabwith a slot provided in the mounting tab, and wherein a fastener extendsthrough the slot in the at least one mounting tab.
 6. The miter saw ofclaim 5 wherein the slot is an elongated slot such that the dust chutemay be moved in a lateral direction when the fastener extends though theslot.
 7. The miter saw of claim 6 wherein the fastener is a screw thatthreadedly engages a hole in the bevel support, the screw furtherincluding a head configured to engage the dust chute when the screw istightened in the hole in the bevel support.
 8. The miter saw of claim 1wherein the dust chute includes a receptacle designed and dimensioned toreleasably hold the laser alignment device on the dust chute.
 9. Themiter saw of claim 8 wherein the receptacle comprises a cup shapedmember configured to receive a cartridge of the laser alignment device,the cartridge including optics and a laser generator.
 10. The miter sawof claim 9 wherein the laser generator is configured to emit a beam oflight along each side of the cutting blade toward the work surface. 11.A miter saw comprising: a table; a cutting assembly; a cutting supportarrangement configured to support the cutting assembly above the table;a dust collection system supported by the cutting support arrangement;and a laser alignment device supported by the dust collection system.12. The miter saw arrangement of claim 11 further comprising areceptacle formed in an upper wall of the dust collection system, thereceptacle configured to receive the laser alignment device.
 13. Themiter saw of claim 12 wherein the laser alignment device is configuredto generate a laser beam, wherein the laser beam is directed toward thetable when the laser alignment device is positioned in the receptacle.14. The miter saw of claim 13 wherein the dust collection systemcomprises a dust collection chute including plurality of mountsconfigured to secure the dust collection chute to the cutting supportarrangement.
 15. The miter saw of claim 14 wherein each of the pluralityof mounts includes an elongate slot defined therein, the elongate slotsconfigured to allow lateral adjustment of the dust collection chute inrelation to a saw blade of the cutting assembly which results in lateraladjustment of the laser beam generated by the laser alignment device.16. A miter saw comprising: a table; a cutting assembly; a cuttingsupport arrangement configured to support the cutting assembly above thetable; a dust collection member supported by the cutting supportarrangement, the dust collection member including an input port, an exitport, and a receptacle; and a laser alignment device retained within thereceptacle of the dust collection member, the laser alignment deviceconfigured to emit light toward the table.
 17. The miter saw of claim 16wherein the dust collection member further includes a funnel bodyextending between the input port and the exit port.
 18. The miter saw ofclaim 17 wherein the receptacle is provided on an upper portion of thedust collection member and is integrally formed with the funnel bodybetween the input port and the exit port.
 19. The miter saw of claim 16wherein the receptacle is positioned above the input port on the dustcollection member.
 20. The miter saw of claim 19 wherein the receptaclecomprises a cup-shaped member configured to retain the laser alignmentdevice.